Foto i Video Oprema > Objektivi

Oznake na objektivima i njihovo značenje

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lancia88:
Pozdrav,

nisam siguran da li negde postoji neki omalen vodic vezan za oznake na objektivima, ali sam sasvim siguran da bi to bila veoma, veoma korisna stvar za mnogo onih koji ili tek ulaze u svet SLR-a ili u njemu tek prelaze na full-frame format senzora.

Mene je svojevremeno zbunjivalo raznoliko oznacavanje kod raznih proizvodjaca, pa sam uspeo nekako da izbistrim da je kod Canona sustinska razlika uglavnom u dva slova: L i S. Prvo oznacava seriju koja predstavlja uglavnom najujednaceniji pod-brend u zoni proizvodnje objektiva i taj zastitni znak uglavnom sugerise kupcu da u toj seriji ima najmanje odstupanja od primerka do primerka, te da se proizvodi drze svojih propisanih standarda, a ti standardi su najvisi koje Canon sebi zadaje. Oznaka S znaci: ne kupuj ako imas Full-frame telo. Dakle, samo sa EF, bez dodatnog S.

Ipak, zbunjivanje je moguce lako i kod drugih proizvodjaca, recimo, oznaka G kod Nikona predstavlja ozbiljan i uglavnom neopravdan proces stednje u proizvodnji izbacivanjem prstena za rucnu promenu blende sa objektiva, dok ta ista oznaka G, predstavlja najbolje sto je Minolta mogla da proizvede, a Sony to kasnije prihvatio...srecom, inace bismo se i tu mucili. Opet, Sony brze-bolje usvaja na Minoltine principe i otuznu proizvodjacku praksu da napravi razlicite objektive za crop i za FF tela, pa otud i njegova nesrecna serija DT proizvoda, koja nije jasno naglasena ali je za alfe 850 i 900 tek nesto upotrebljivija nego EF-S za Canona...slicno kao i kod Nikona, mozes da nasrafis ali rezultati su isti kao da si na krop telu slikao.

Kod Sigme to zvuci nekako uredjenije, pa imamo oznake DC i DG koje oznacavaju format tela za koje je predvidjen objektiv (C za crop, G za FF), dok smo sa APO oznakom kudikamo zadovoljniji nego bez te oznake sa objektivima. Sad se tu vec mesaju i druge oznake, kao EX i slicno, koje kao da sugerisu - nemam pojma kako al' ovaj nam je objektiv ispao bas super.

Iako i kod Sigme postoji mnostvo zbunjujucih oznaka, kod Nikona (DX i FX oznacavaju formate ali tih oznaka vise nema nego sto ima po objektivima), Tamrona ili Tokine tek jako tesko mozemo prepoznati o kom se formatu radi. Nikon jako cesto koristi oznaku D na svojim objektivima koja nista od toga ne objasnjava, a neophodno mu je bilo i uvodjenje oznake AF-S sa naglaskom na zadnje slovo, da oznaci objektive koji se ne oslanjaju na motoriku fokusiranja u samom telu, obzirom da su otkrili rupu u saksiji svojom izuzetnom inovantnoscu i konstrukcijom serije osakacenih aparata kao sto su D40/40x/60 i time uslovili korscenje inace veoma dobrih aparata kupovinom AF-S objektiva da bi se postigao komfor autofokusa.

E sad, ima li neko ovde potkovaniji od mene da pokusa brend-po-brend da pojasni bar osnovne oznake a da to pritom bude sve na jednom mestu, makar za najkoriscenije brendove?

Na net-u ima kojekakvih oznaka, to stoji, ali nigde nema tako sublimirano na jednom mestu, na srpskom jeziku i objasnjeno sta u sustini predstavlja sta u realnom radu od svega navedenog. Pod ovim podrazumevam da, recimo, AF znaci autofokusne mogucnosti i to je prilicno jasno, ali, primera radi, sta u realnom radu znaci Aspherical, odnosno taj sistem nabijanja staklica i plasticni cilindar :)

tik-tak:
odlicno pitanje jos samo da nadjemo odgovor...  ;D

Zoran Rodic:
Sferična sočiva imaju problem da svetlo iz centra i sa krajeva dovedu u istu ravan, što se manifestuje neoštrim fotografijama u centru a oštrim na krajevima ili suprotno.
Ta anomalija se zove ‘’sferična aberacija’’
Da bi se to izbeglo, stavljaju se  skuplja i komplikovanija za pravljenje, Asferična sočiva koja vrše  korekcije ugla pod kojim svetlost pada na senzor.
To slikovito, izgleda ovako




Što se tiče prvog dela pitanja, to je jedan obiman posao … skupiti pa prevesti … uf.  :-\
Ajde da za početak razlučimo da li bi ti koristilo recimo ovako nešto http://www.sigmaphoto.com/sigma-lens-technology ... tog tipa, to je već manji problem, tu mogu da ti nabacam par korisnih linkova, sličnog tipa.

Zoran Rodic:
Evo, valjda su sve ovce na broju :)

Canon
EF : Lens mount designation for Canon's current camera system. Stands for Electronic Focus.
EF-S : Lens mount designation for Canon's current APS-C digital SLRs (reduced sensor size), for example the 20D, 350D, and 300D models. The S stands for "short back focus," implying that the rear element of the lens is closer to the sensor than with regular EF lenses. EF-S lenses will not mount on Canon film SLRs or Digital SLRs that do not have an EF-S mount.
TS-E : Tilt-shift lens, for control of perspective and depth of field.
MP-E : Macro Photo Electronic. These lenses do not have autofocus, the "electronic" refers to the electronic aperture control. Specialised lenses designed for macro photography.
L Lenses : L refers to Canon's professional range of lenses. Many people take the L to stand for Luxury. Purchases of such lenses can lead to 'L Fever', a condition where all future lense purchases must be L class.
IS : IS refers to Image Stabilisation, Canon's anti-shake feature. Also known as VR (Vibration Reduction - Nikon), OS (Optical Stabilisation - Sigma).
USM : USM refers to the autofocus motor. Ultrasonic Motors (USM) are piezoelectric and offer very fast and silent autofocusing. There are two types: A standard cheaper micro-USM which just replaces the regular electromagnetic AFD motor, and a Ring USM (internal focus) which is much faster and also incorporates fulltime manual focus overide without leaving AF mode (or damaging the focus mechanism).
AFD : An older type of AF motor, AFD (Arc-Form drive) is generally slower and noisier than USM.
DO : Diffractive Optics - DO lenses are found with green rings (as opposed to the red ring around the L-series lenses) to set them apart. DO considerably cuts the size and weight of a lens down while maintaining quality. Still not as sharp as a true L lens but in many cases a viable alternative when size or portability are a concern. How DO works you can read at http://diffractive-optics.org/
A note about the maximum aperture The maximum aperture in a 135mm F/2 lens is (135/2) = 67mm. This means the hole that lets the light in opens up to 67mm. This explains why lenses with larger apertures are more expensive: they require more glass inside larger barrels.

Nikon

AF-I Internal auto-focusAF-D/G with auto-focus motor built into the lens barrel itself
AF-S Silent-wave auto-focusAF-D/G with ultrasonic AF motor
ASP ASPherical lens elements A type of lenses that virtually eliminates the problem of coma and other types of lens aberration. The are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
CRC Close Range CorrectionProvides superior image quality at close focusing distances and increases the focusing range
D (AF-D) Lens equipped with a chip which allows the body to assess the distance to the object being photographed and exposes for that object correctly
DC Defocus-image ControlA creative feature for photographers; control the degree of spherical aberration
DX Digital eXpandedLenses for DSLRs with a smaller sensor than 35mm
ED Extra-low DispersionPrevents chromatic aberration because it concentrates and directs the wavelength of the light more effectively onto the camera's sensor
G (AF-G) Same as AF-D, but without an aperture ring
IF Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
N Nano coatingNon-reflective coating for clearer images with increased detail by reducing reflection from inside the lens
RF Rear FocusThis lens is equipped with a system that moves the rear lens group for focusing SIC Super Integrated CoatingMultilayer coating of the optical elements in lenses
SWM Silent Wave MotorUltrasonic AF motor
VR Vibration ReductionA family of techniques used to reduce blurring associated with the motion of a camera. Specifically, it compensates for pan and tilt of a camera

Sigma

EX : An abreviation for the "Excellence" range of lenses. These lenses are similar to Canon's L series, claimed to be superior in build and optical quality to regular lenses. Like the L series they have a distinctive exterior.
DG : A DG lens can be used with both 35mm SLR and digital SLR cameras. DG refers to additional optical coatings that are meant to minimize reflections of light off the sensor itself.
DC : A DC lens is designed so the image circle matches the smaller size of a digital SLR's image sensor compared to a 35mm frame. These are typically lighter than DG lenses but are not suitable for 35mm SLRs.
ASP: An aspherical lens, which is more compact than conventional lenses.
APO: APO or apochromatic lenses are made using a low dispersion glass to reduce chromatic aberration.
OS: Optical Stabiliser. More or less identical to Canon's IS and Nikon's VR.
HSM: "Hypersonic Motor," which in the same way as Canon's USM is used to power the autofocus mechanism and is generally quieter and faster than conventional electromagnetic motors.
RF: Rear focus lenses move the rear lens elements delivering faster, more quiet focusing.
IF: Inner focus lenses move the middle lens elements which does not change the lens' overall length when focusing. This results in better stability, which is useful for telephoto shooting.
DF: A dual focus lens. The focus ring on the lens pushes forward and backwards dis-engaging it so it does not rotate during autofocus.
Conv: These lenses are compatible with Sigma's teleconverters without and retain proper automatic exposure function.

Tamron

AD Anomalous DispersionSpecial optical glass which delivers large partial dispersion ratios relative to a specific light wavelength zone
ASL Aspherical Lens elements A type of lenses that virtually eliminates the problem of coma and other types of lens aberration. They are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
Di Digitally integrated design Optical system designed to meet the performance characteristics of DSLR cameras as well as film cameras
Di II Digitally integrated design Lenses made exclusively for DSLR cameras with APS-C sensors
HID High Index High Dispersion glass Minimises on-axis and lateral chromatic aberrations
IF Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
LD Low DispersionLow Dispersion elements which effectively compensate for chromatic aberration that is a problem at the telephoto end and lateral aberration at the wide angle end SP Super PerformanceThe first priority in producing these lenses have been superior specifications and outstanding performance free from cost restraints
USD UltraSonic Silent DriveUltrasonic AF motor
VC Vibration Compensation - A family of techniques used to reduce blurring associated with the motion of a camera. Specifically, it compensates for pan and tilt of a camera
XR eXtra RefractiveHi Refraction index glass elements resulting in minimum aberration. Allows smaller lens diameters while maintaining aperture values for overall compactness
ZL Zoom LockPrevents undesired barrel extension


Tokina

ASA  : – spherical -  A  type of lenses that virtually eliminates the problem of coma and other types of lens aberration. The are particularly good at correcting distortion in wide-angle lenses as well as contributing to a lighter and smaller lens design
AT-X :  Advanced Technology eXtraLenses that are manufactured without compromises, using the most advanced design and fabrication technologies available
D :  Digitally optimized coatings
DX :  Only compatible with a cropped sensor (APS-C)
F&R :  Front and Rear asphericalAspherical molded glass element in the front and in the rear FC Focus ClutchOne-touch focus clutch allows the focus to be moved quickly from the AF position back into the MF position
FE :  Floating Element
HL  : DHigh Refraction, Low Dispersion
IF : Internal FocusTo ensure stability in focusing, this lens moves the inner lens group or groups without changing the lens' physical length
IRF : Internal Rear FocusThis lens is equipped with a system that moves the rear lens group for focusing
PRO : Lenses that have hardened Alumite (Armalite) finish to increase durability
SD : Super Low DispersionPrevents chromatic aberration because it concentrates and directs the wavelength of the light more effectively onto the camera's sensor

Pentax

K : Is the first generation K mount lens, Manual Focus, Manual Exposure. (Listed as Pentax smc)
M : Second generation of K mount lens, smaller then their K counterparts, manual focus manual exposure
A : First Auto exposure lenses from Pentax, manual focus.
F : First generation Auto Focus, Auto exposure lens
FA : Second generation Auto Focus, Auto Exposure lens, On board chip contains lens MTF data for Hyper Program compatible bodies
FA-J : Similar to FA lenses but don’t have an aperture ring.
DA : Digital Lenses, no aperture ring, some have reduced images circle some don’t, Digital coatings and optimised construction.
D-FA : Digital Lenses, aperture ring, covers a 35mm frame. Digital coatings and optimised construction.
* (star) lens : Pentax’s equivalent to Canon’s L, lenses of exception quality. (A, F, FA)
DA* : Pentax’s High spec Digital lenses, Exceptional quality, weather sealed, SDM (Super Sonic Direct drive Motors)
Limited : A prime lens of unparalleled image quality and construction, hand made to the highest quality.
AL : A lens that uses one or more aspherical elements to help improve wide angle performance and sharpness.
ED : A lens that uses extra-low dispersion glass elements reduces chromatic aberrations.
IF : A lens that uses an internal focusing mechanism.
SDM : Super Sonic in lens lens AF motors, silent and accurate Autofocus.
Fixed Rear Element Extension (FREE) : A lens whose last element group remains fixed during focusing.
SMC : Pentax’s lens coating technology.
Quick Shift : Allows manual adjustment of AF after AF lock has been achieved.
PZ : Power Zoom, and Electronic zoom function on KAF-2 mount FA lenses, only functional on Z series FSLRs and K10D digital body.

lancia88:
Pozdrav,

tjah, nije ovo samo meni interesantno, odnosno, ja sam ionako tu negde da svarim sve oznake koje su mi potrebne ali nekako cenim da je opste upotrebljiva stvar. Naravno, ukljucujuci i objasnjenje sta se kojom oznakom dobija ili gubi u praksi.

Apropo linka, pojedine stavke su objasnjene a pojedine zahtevaju i dodatna objasjnenja.


SIGMA

ASP - nacin izrade objektiva u kome se postize relativno podjednaka ostrina i u centru i na krajevima, tako sto se dodaju Asfericna sociva koja vrse  korekcije ugla pod kojim svetlost pada na senzor. Manji broj upotrebljenih elemenata, manja tezina i gabariti. Dakle, trebalo bi da ima dodatnu upotrebnu vrednost u realnom radu.

APO - posebna stakla koja omogucuju kompenzaciju pojave hromatskih aberacija (problem boje na prelazima) koristenjem svojih svojstava niske disperzije svetla kroz sociva. Ovo bi narocito trebalo da ima realan odziv u praksi u smislu kvaliteta fotografije.

OS - ono sto Canon krsti kao IS, a Nikon kao VR, dok Sony zove osnovnom opremom  ;D , Sigma naziva OS (opticka stabilizacija) kojom uspeva da plivajucim elementom kompenzuje sitne titraje ruke, daha i svega drugog sto utice u jako malom fizickom opsegu i posebno kratkom vremenskom intervalu na kvalitet slike, ali sa povecanjem udaljenosti objekta i smanjenjem svetla koje pada na njega, drasticno urusava sliku. Posebno na vecim daljinama (recimo preko 85mm ekv) izuzetno korisna stvar. Naravno, postoji i deo koji se odnosi na kontraefekat ukljucene stabilizacije ali to su specificnosti i anomalije a ne pravila.

HSM - Highspeedmotor omogucava brzo autofokusiranje. Za dobar deo potreba prosecnog fotografa, a narocito iz domena Life, sportske i slicnih fotografija, veliki pomak unapred svakako. Nisam siguran da bih za ovo doplacivao kod fotografisanja pejzaza, portreta, studijske fotografije svih profila i slicno ali ako ta razlika u ceni ne bi bila preterano uocljiva, verujem da bi ucinila objektiv upotrebljivijim. Cenim da je najveca upotrebna vrednost ovog elementa u podrucju 70 pa sve do krajnjih milimetraza, ali najpre u dijapazonu do 200-250mm u kome se najcesce slikaju elementi Life fotografije ili sportska desavanja.

RF - zadnji fokus, odnosno element za Highspeed kontrolu nalazi se u zadnjem delu sto smanjuje zvucni dozivljaj fokusiranja koji je ujedno jedan od zastitinih znakova Sigme. Dosta se umeju cuti, njima bas treba prigusivac. Ipak, koliko se razlikuju od primerka do primerka, kad pogodi covek ostar i potpuno ispravan primerak, uglavnom ne trazi 'leba preko pogace vec otrpi tu buku.

IF - funkcionalnost objektiva, izmedju ostalog, uslovljena je i stvarima na koje uglavnom ne obracamo paznju robujuci stereotipu. Jedan od tih stereotipa na koji se navikavamo kao na normalnu stvar jeste izbacivanje dela objektiva sa socivom unapred, cime mu se menja fizicka duzina. Nedavno sam vec procitao to zapazanje i ovde na forumu, kako u makro podrucju to ume da bude problem, sto ce reci da ukoliko se unutrasnji element pomera i time koriguje ziznu daljinu, a da se pritom ne menja fizicka duzina objektiva, to moze itekako da predstavlja dobitak u realnom radu. IF oznacava upravo to (Inner focus). Naravno, za fotografisanje bilo cega sem makro fotografije, tesko da bismo nasli ekonomsko opravdanje za doplacivanje ove opcije. Ona se verovatno i ne doplacuje direktno vec se kroz razliku u ceni otprilike moze utvrditi koliko ova tehnologija kosta po primerku, i to za one modele koji imaju slicne karakteristike i uglavnom ih razlikuje postojanje IF funkcije na jednom od njih.

CONV (APO Teleconverter EX) - oznaka da se takvo socivo moze koristiti sa adekvatnim telekonveretrom navedenih oznaka. Funkcija telekonvertera jeste "produzavanje" dometa, i realno ima siroku primenu u fotografiji. Ipak, veoma je bitno da se naglasi da je upotreba i wide i tele konvertera uslovna, odnosno da moze izobliciti ili cak upropastiti fotografiju i zahteva odredjenu pripremu i upotrebu samo u odredhjenim uslovima. Naravno, kao i svuda i kod konvertera proizvodjac, odnosno hardver igraju veliku ulogu. Stoga ovde Sigma nudi potpunu saradnju ako sam dobro protumacio sa navedenim tipom konvertera. Vrlo korisno ukoliko je covek spreman na izdatak kupovine bas tog konvertera. Beske puca sa konverterom, mozda bi on mogao da ovo malo strucnije objasni i eventualno pokaze ako imadne vremena nekad :)

EX - e to je sad ona oznaka za najbolje&najlepse sto ume Sigma. Imam neke od ovih objektiva na raznim sistemima, ali nemam, a ne secam se ni da sam imao nekad, objektive ekvivalente, samo bez tih oznaka. Sa ovom oznakom su tu negde, junacki se drze sa OEM, bar koliko sam ja uspevao da procenim. Ima ovde i ljubitelja i pljuvatelja Sigme, a EX markirani objektivi verovatno jedini mogu da se upotrebe u komparacijama, bilo da se radi o hvaljenju, bilo o kudjenju.

DG - objektivi za Full-frame format tela. Jedini upotrebljivi za ovaj format, nema sumnje u njihovu sustinsku korisnost.

DC - objektivi za tzv. krop tela, najveca vrednost ove oznake je kod trazenja FF objektiva - pomazu u eliminaciji :)

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